Method for removing heavy metals from media containing heavy metals by means of a Lyocell moulded body, cellulosic moulded body comprising absorbed heavy metals, and the use of the same

ABSTRACT

The invention relates to a method for the adsorption of heavy metals from media containing heavy metals, using a Lyocell moulded body. The invention also relates to a cellulosic moulded body comprising adsorbed heavy metals and the use of the same as an antibacterial and/or fungicidal moulded body.

The invention relates to a method for the adsorption of heavy metalsfrom media containing heavy metals, using a Lyocell moulded body. Theinvention also relates to a cellulosic moulded body comprising adsorbedheavy metals and the use of the same as an antibacterial and/orfungicidal moulded body.

Methods for removing heavy metals from media containing heavy metals areknown. In these methods, problems arise with diluted waste water orindustrial process water flows, whereby the main cause behind theseflows is the drag-out from process stages, often caused by rinsingoperations.

In WO 89/00444, therefore, a method for separating nickel ions fromaqueous solutions is described. For this purpose, the solution issubjected to liquid membrane permeation in a first stage and, in asecond stage, the remaining nickel is removed using solvent extraction.

Although it is attempted to limit the amount of rinse water by usingoptimised rinsing concepts, useful materials and auxiliary agents arealso carried along with the pollutants. What is required, therefore, isa closure of circuits for intra-plant material and water, whereby thewaste waters that arise in the process should be further cleaned up.

In WO 00/63470, a method for manufacturing cellulosic moulded bodieswith a high adsorbing capacity is described, whereby an ion exchanger isadded to the cellulose fibre during its manufacture. The ion exchangercan have a polystyrene or polyacrylate basis, in particular acidic oralkaline derived styrene-divinylbenzene copolymer resins or acrylicacid-divinylbenzene copolymer resins. The moulded bodies obtained aresuitable for eliminating the temporary hardness and heavy metals fromwater.

Furthermore, a method for recovering metals from alkaline metalsolutions that contain ammonia is described in U.S. Pat. No. 4,500,396,whereby a weakly acidic material, capable of cation exchange, is used,where this material is a polymeric fibrous web with monomers containingcarboxyl groups grafted onto it. The polymeric fibrous web can consistof nylon, cellulose, polyethylene or polytetraethylene fibres ormixtures of these.

Furthermore, a method for recovering copper is also described in U.S.Pat. No. 4,500,396. Carboxyl groups are grafted to felt made of polymerfibres by means of radiation. In this way, one obtains a cationexchanger, with which the copper can be filtered out of the wastewaters.

The known methods have the disadvantage that, on the one hand, syntheticion exchangers are added to the moulded bodies used in the process andthese are therefore not biodegradable, and, on the other hand, thedurability of the moulded bodies suffers from the addition of the ionexchangers. In addition, the manufacture of the moulded bodies requireseffort, because these bodies must be modified with functional groups.Before use, the ion exchanger groups, such as carboxyl groups, requireadditional treatment with acid, lye or salts in order to activate thegroups, as a result of which the method requires effort to carry out.

Furthermore, fibres, fibrous webs and sponges are known that contain ametal with an antibacterial effect.

Consequently, an antibacterial fibre is described in U.S. Pat. No.5,496,860 that includes a fibre capable of ion exchange and a metal ionwith an antibacterial effect, that is bonded via an ion exchangereaction. The fibres contain sulfonic acid groups or carboxyl groups asgroups capable of ion exchange.

The known antibacterial fibres and methods described in the precedinghave the manufacturing disadvantage that active groups, capable of ionexchange, are introduced after the normal fibre manufacturing process,and these then have to be activated with metal ions in a further step.

Furthermore, a stratiform antibacterial fibrous web is described in U.S.Pat. No. 5,652,049 that consists either of synthetic fibres withzeolites in which Zr or Ag ions are incorporated or of cellulose fibreswith chitosan particles.

Furthermore, a body that is germicidal and that absorbs urine, faecalsubstances and blood is described in DE 31 35 410; this body contains awater-soluble copper salt that is not irritating or damaging to humanskin, and which is concentrated in the surface that first comes intocontact with the separation products. The material used for themanufacture of such bodies is a cellulose fibre fleece or wadding thatconsists of native cellulose (fluffed sheets). This native cellulosemust be sprayed and treated in order to be able to adsorb a slightamount of pollutants.

Therefore, the adsorption of the antibacterial substances is poor and,in particular, the result is uneven absorbing of these substances, whichconsequently also results in an uneven release and effect of theantibacterial properties.

A further example of a method for the manufacture of antibacterialfibres is described in U.S. Pat. No. 5,458,906, whereby the fibres areimmersed in a solution with monovalent copper ions and a solution withcarbonate, borate and mixtures of the two. The fibres can be natural orsynthetic fibres, such as acrylic fibres, grafted cotton, wool, linen orfibre mixtures.

These antibacterial fibres and methods for their manufacture have thedisadvantage that the base product is a “finished” fabric or fibre, theabsorbing of the active antibacterial substances takes place only on thesurface, and the active substances are not uniformly and homogenouslyincorporated during the spinning process.

The object of the invention under consideration is therefore to solvethe problems of the known methods and fibres described in the preceding.In particular, the object of the invention is to provide a simple,economical and reliable method for removing heavy metals from mediacontaining heavy metals and a reliable antibacterial and/or fungicidalmoulded body that is also easy to manufacture.

The solution of the object is a method for removing heavy metals frommedia containing heavy metals, whereby the medium containing heavymetals is brought into contact with a Lyocell moulded body.

A further solution is a cellulosic moulded body, whereby at least oneheavy metal is adsorbed on it, as well as its use as an antibacterialand/or fungicidal material.

To be understood under the term “Lyocell moulded body” in the sense ofthis invention is a moulded body that is obtained in a known way bydissolving cellulose in an amine oxide hydrate, preferablyN-methylmorpholine-N-oxide (NMMO) monohydrate, and introduction of thesolution into a non-solvent for the cellulose, preferably water, bymeans of which the moulded body precipitates in the non-solvent. In thisway, a Lyocell moulded body is obtained, whereby the cellulose thatforms the moulded body is not modified with additional functionalgroups, in particular, sulfonic acid or carboxyl groups, i.e., it isunmodified cellulose. The cellulose forming the moulded body can containcustomary additives, as well as other natural and/or synthetic polymers,as described in the following, and can also be subjected to customaryaftertreatment processes.

It was a surprise to discover that the Lyocell moulded body manufacturedin this way is excellently suitable for removing heavy metals from mediacontaining heavy metals, because this body adsorbs a large amount ofheavy metals without additional functional groups. It is assumed thatthe adsorption of the heavy metals takes place on the Lyocell mouldedbodies via its free carbonyl, carboxy and/or hydroxyl groups.

The Lyocell moulded body can be present as a regenerated moulded body orin a modified incorporated form, and can be used in the method accordingto the invention as an ion exchanger, adsorption filter or filteringmaterial, in order to remove the heavy metals contained in aqueoussolutions or gases from the same.

Preferably, heavy metals selected from the group consisting of Ag, Cu,Zn, Hg, Sn, Cd, As, Pb, Sb, Zr, Ni, Fe, Au, Pd, Pt, Ir and mixtures ofthese in metallic, ionic or complexed form can be removed from themedium with the method according to the invention. Media containingheavy metals mainly arise in aqueous waste material, such as inmetallurgical works or during metal recycling processes, and these wastematerials are not permitted to be dumped without removing the substancescontained in them that are damaging to the environment. A furtherapplication area for the method according to the invention is therecovery of valuable heavy metals from consumed solutions, such assolutions containing copper, which arise during the manufacture ofsemiconductor plates, and from photographic baths containing silver.

Further preferred application areas for the method for removing heavymetals according to the invention are:

Chemical Industry:

-   -   Treatment and recovery of waste water and process solutions for        removing heavy metals, particularly during the manufacture and        disposal of batteries and storage batteries;    -   Recycling of useful solutions, particularly removal of Hg and        heavy metals of alkali chloride electrolysis brines;    -   Pd recovery in the mirror metallizing and battery industries;    -   Ag recovery in the semiconductor industry; and    -   Ag recovery from photographic developing baths.        Metal Extraction/Electroplating/Metal Surface Treatment:    -   Cycling of process solutions;    -   Waste water fine cleaning, particularly in the electroplating,        chromatizing and semiconductor industries during degreasing,        etching, galvanizing, anodic oxidation, hot-dip galvanizing,        painting, etc.;    -   Recovery and thereby service life extension of baths,        particularly in the electroplating, chromatizing and        semiconductor industries.        Environmental Engineering:    -   Removal of heavy metals, such as mercury and chromate, from the        groundwater;    -   Treatment of leachate from landfills to reduce the heavy metal        content;    -   Removal of heavy metals and mercury from waste waters from flue        gas purification in incineration plants, mainly household refuse        incineration plants.

Using methods according to the invention, new concepts and proceduralsolutions can be realised. Consequently, by using conventional watertechnology, such as membrane processes (micro, ultra and nanofiltration; reverse osmosis), liquid membrane permeation, electrolysisprocesses, crystallization, solvent extraction, activated carbonfilters, circuits can be closed through the use of Lyocell mouldedbodies according to the invention.

After the use of the Lyocell moulded body in the method according to theinvention, useful materials, such as silver, copper or tungsten, cansimply be fed back into the process by subjecting the Lyocell mouldedbody, such as filtering material, used according to the invention toincineration or acid treatment.

The method according to the invention can also be advantageously usedfor removing heavy metals from cigarette smoke, such as Cd, i.e., theLyocell moulded body can be used as a filtering material in cigarettes.In particular, a Lyocell moulded body in the form of filtering materialcan be used as a cigarette filter.

By carrying out the method according to the invention, from roughly 1 toroughly 100 g/l of heavy metals, depending on the type of heavy metal,heavy metal concentration, temperature, detention time andliquid-to-solid ratio, i.e., the ratio of fibres to waste water, can beremoved from the medium containing heavy metals.

In a further, especially preferred embodiment, a plant and/or animalmaterial can additionally be added to the Lyocell moulded body used inthe method according to the invention. The plant and/or animal materialis preferably a material made of marine plants or marine animals.

The material of marine plants is preferably selected from the groupconsisting of algae, kelp, eel grass, particularly algae. Examples foralgae include brown algae, green algae, red algae, blue algae ormixtures of these. Examples of brown algae are Ascophyllum spp.,Ascophyllum nodosum, Alaria esculenta, Fucus serratus, Fucus spiralis,Fucus vesiculosus, Laminaria saccharina, Laminaria hyberborea, Laminariadigitata, Laminaria echroleuca and mixtures of these. Examples of redalgae include Asparagopsis armata, Chondrus cripus, Maerl beaches,Mastocarpus stellatus, Palmaria palmata and mixtures of these. Examplesof green algae are Enteromorpha compressa, Ulva rigida and mixtures ofthese. Examples for blue algae are Dermocarpa, Nostoc, Hapalosiphon,Hormogoneae, Porchlorone. Classification of the algae can be found inthe textbook Botanik für Hochschulen E. Strasburger; F. Noll; H. Schenk;A. F. W. Schimper; 33rd edition, Gustav Fischer Verlag,Stuttgart-Jena-New York; 1991.

The material made of marine plants can be obtained in the known way.

First, the material made of marine plants is harvested. The harvestedmaterial can be further processed in a variety of ways. The material ofmarine plants can be dried at temperatures of up to 450° C. and can bereduced to small pieces using ultrasound, wet ball mills, pin mills orcounter-rotating mills, by means of which a powder is obtained, whichcan optionally also be fed through a centrifugal stage forclassification. A powder obtained in this way can already be added to aLyocell moulded body that can be used according to the invention.

Furthermore, this powder made of a material of marine plants can inaddition be subjected to an extraction process, for example, with steam,water or an alcohol, such as ethyl alcohol, as a result of which aliquid extract is obtained. This extract can also be used as an additiveto the Lyocell moulded body that can be used according to the invention.

The harvested material of marine plants can also be subjected to acryogenic process to reduce it to small pieces. In this process, it isreduced to small particles with a size of approximately 100 μm at −50°C. If required, the material obtained in this way can be further reducedto small pieces, whereby particles with a size of approximately 6 toapproximately 10 μm are obtained.

The material from the outside shells of marine animals is preferablyselected from oceanic sediments, shells of shrimp or bivalves, lobsters,crustaceans or prawn, reduced to small size, and/or coral.

In the case of oceanic sediments, the material from marine animal shellscan be used directly. If material from the shells of shrimp or bivalves,lobsters, crustaceans and/or prawn is used, the material must be reducedto small pieces.

It is also possible to use a mixture of materials from marine plants andshells from marine animals, as well as the extracted products. Thequantitative composition of material of marine plants and shells ofmarine animals is preferably 50% by weight to 50% by weight. Preferably,material from marine plants is used according to the invention.

It is furthermore possible to use particles of the material of marineplants and/or shells of marine animals in the particle size range from200 to 400 μm, preferably 150 to 300 μm. Preferably, particles withsmall particle sizes, such as 1 to 100 μm, more preferably 1 to 5 μm,are also used. It is also possible to use uniform materials or differentalgae materials with mixed particle sizes

An example for a usable material of marine plants is a powder ofAscophyllum nodosum with a particle size of 95%<40 my, which contains5.7% protein by weight, 2.6% fat by weight, 7.0% fibrous components byweight, 10.7% moisture by weight, 15.4% ash by weight and 58.6%hydrocarbons by weight. Furthermore, it contains vitamins and traceelements, such as ascorbic acid, tocopherols, carotene, barium, niacin,vitamin K, riboflavin, nickel, vanadium, thiamine, folic acid, folinicacid, biotin and vitamin B₁₂. In addition, it contains amino acids, suchas alanine, arginine, aspartic acid, glutamic acid, glycine, leucine,lysine, serine, threonine, tyrosine, valine and methionine.

The material of marine plants and/or shells of marine animals can bepresent in the Lyocell moulded body in an amount of 0.1 to 30% byweight, preferably 0.1 to 15% by weight, more preferably 1 to 8% byweight, particularly 1 to 4% by weight, relative to the weight of theLyocell moulded body. In particular, if the Lyocell moulded body is inthe form of a fibre, the amount of material of marine plants and/orshells of marine animals is preferably 0.1 to 15% by weight,particularly 1 to 5% by weight.

The continuous or discontinuous mixing of cellulose and the material ofmarine plants and/or shells of marine animals can be accomplished withdevices and processes as described in WO 96/33221, U.S. Pat. No.5,626,810 and WO 96/33934.

In the method according to the invention, the Lyocell moulded body ispreferably used in the form of fibres, filaments, fibrous webs, foils,films, membranes, sausage casings, filter paper, particularlymanufactured using short cut fibres 3-15 mm in combination with othermaterials like cellulose, and non-wovens.

In a preferred embodiment, the Lyocell process can be carried out byintroducing the plant and/or animal material, as described in thefollowing. To manufacture a workable mass, a solution of cellulose,NMMNO and water is manufactured by means of first forming a suspensionof cellulose, NMMNO and water and then continuously transporting thissuspension in a 1 to 20 mm thick layer under reduced pressure through aheat exchange surface by means of rotating elements. During thisprocess, water is evaporated until a homogenous cellulose solutionresults. The amount of cellulose in the cellulose solutions obtained inthis way can be from 2 to 30% by weight, the amount of NMMNO can be from68 to 82% by weight, and the amount of water can be from 2 to 17% byweight. If required, additives, such as inorganic salts, inorganicoxides, finely dispersed organic substances or stabilizers, can be addedto this solution.

Then the plant and/or animal material, particularly the material ofmarine plants and/or shells of marine animals, in the form of powder,powder suspension or in liquid form, as an extract or suspension, iscontinuously or discontinuously added to the cellulose solution obtainedin this way.

Depending on the method, the plant and/or animal material, particularlythe material of marine plants and/or shells of marine animals, can alsobe added after or during the continuous reduction of the dry celluloseto small pieces, for example, in the form of algae material in theoriginal size, as a powder or highly concentrated powder suspension. Thepowder suspension can be produced in water or any other solvent in theconcentration required and necessary for the method.

Furthermore, it is also possible to feed the material of marine plantsand/or shells of marine animals to a mashing process with simultaneousreduction to small size. The mashing can be carried out either in water,in lye or also in the solvent that is needed for dissolving thecellulose later. In this case, as well, the material of marine plantsand/or shells of marine animals can be added as a solid, powder orsuspension, or also in liquid form.

The polymer composition enriched with the material of marine plantsand/or shells of marine animals can, in the presence of a derivationagent and/or a solvent known for the dissolving process, be convertedinto a workable extrusion mass.

A further possibility for adding the material of marine plants and/orshells of marine animals is addition during a continuous dissolvingprocess, such as described in EP 356419 and U.S. Pat. Nos. 5,049,690 and5,330,567.

Alternatively, the addition can be carried out discontinuously whilemaintaining a master batch of the cellulose solution. Preferably, thematerial of marine plants and/or shells of marine animals are addedcontinuously.

The material of marine plants and/or shells of marine animals can beadded in any other stage of the moulded body's manufacturing process.For example, it can be fed into a pipeline system with the correspondingmixing by system-contained static mixing elements or stirring elements,such as known inline refiners or homogenizers, i.e., Ultra Turraxdevices. If the method is carried out in continuous batch operation,e.g., using a stirred vessel cascade, the algae material, in solid,powder, suspension or liquid form, can be introduced at the positionthat is the most nearly optimal for the process. Dispersion can beachieved with known stirring elements that are coordinated to themethod.

Depending on the particle size used, the formed, incorporated extrusionor spinning mass can be filtered before or after being incorporated.Conditional on the fineness of the product used, it is also possible todo without filtration in spinning processes with large nozzle diameters.

If the spinning masses are very sensitive, the material can be added inthe suitable form through an injection point directly before thespinning nozzle or the extrusion tool.

A further possibility, if the algae material is present in a liquidform, is to add this material to the continuously spun thread during thespinning process.

The cellulose solution obtained in this way can be spun using aconventional process, such as dry-jet-wet, wet-spinning, melt blownprocess, centrifugal pot spinning, funnel spinning or dry spinning. Thepatent specifications U.S. Pat. Nos. 5,589,125 and 5,939,000, as well asEP 0574870 B1 and WO 98/07911 describe spinning processes formanufacturing cellulose fibres according to the NMMO method. Wherenecessary, the formed moulded bodies are subjected to the conventionalaftertreatment processes for chemical fibres for filaments or staplefibres.

In addition to the spinning methods, there are also extrusion methodsfor manufacturing flat films, round films, casings (sausage casings) andmembranes.

The use of a Lyocell moulded body that contains plant and/or animalmaterial, particularly algae material, in the method according to theinvention, as described in the preceding, has the additional advantagethat, in the method according to the invention, the Lyocell moulded bodyis capable of exchanging Ca, Mg and Na ions and, furthermore, up to 50%more heavy metals can be bonded to it than when a pure Lyocell mouldedbody is used.

Therefore, in this embodiment, the method according to the invention isparticularly suitable for treating media containing heavy metals inapplication areas as described in the preceding. Particularly when aLyocell moulded body that contains material from marine plants is used,the method according to the invention has the advantage that heavymetals are absorbed across the entire cross-section of the Lyocellmoulded body, like a fibre. In this way, a larger amount of heavymetals, referred to the weight of the moulded body, can be absorbed thanwhen a cellulose moulded body with function groups is used.

A further solution of the object of the invention is a cellulosicmoulded body with at least one adsorbed heavy metal on it, whereby theheavy metal can be present in the form of a metallic, ionic or complexedform.

The cellulosic moulded body is preferably selected from the groupconsisting of cellulose regenerated moulded bodies, such as carbamate,viscose and Lyocell moulded bodies, particularly preferred, a Lyocellmoulded body.

The content of the heavy metals adsorbed on the cellulosic moulded bodyaccording to the invention is preferably at least roughly 1 mg/kg,preferred at least roughly 10 mg/kg, particularly preferred at leastroughly 70 mg/kg, preferably at least roughly 200 mg/kg, more preferredat least roughly 500 mg/kg, particularly at least roughly 1000 mg/kg,referred to the total weight of the cellulosic moulded body.

Preferred is the heavy metal selected from the group consisting of Ag,Cu, Zn, Hg, Sn, Cd, As, Pb, Sb, Zr, Ni, Fe, Au, Pd, Pt, Ir and mixturesof these, particularly metals with germicidal effects such as Ag, Cu,Zn, Zr and mixtures of these. In particular, heavy metals with anantibacterial and/or fungicidal effect are used. The expression “heavymetal” in the sense of the invention includes metallic, ionic andcomplexed forms of the heavy metals. Ionic forms include salts andoxides of the heavy metals. A particularly preferred oxide is silver(I)oxide and a particularly preferred salt is silver nitrate. Furtheroxides that can be used are AgO as well as further Ag(I) and Ag(III)oxides, such as Ag₂O₃. Further salts that can be used are silverchloride, silver sulphide, silver proteins, silver carbonate, and thesoluble silver salts silver acetate, silver sulphate, silver citrate,silver lactate and silver picrate.

In one embodiment of the cellulosic moulded body according to theinvention, a plant and/or animal material is added to this body, asdescribed in the preceding. In this way, the result is a very uniformdistribution of the at least one heavy metal in the cellulosic mouldedbody according to the invention. This has the advantage that, on the onehand, a large amount of heavy metal can be introduced into the mouldedbody and, on the other hand, a very uniform release of the adsorbedheavy metal takes place.

The cellulosic moulded body according to the invention can also containother natural and/or synthetic polymers in addition to cellulose, wherethese polymers can either be added to the spinning composition or canalso be present in mixtures as bi-component and multi-component fibresin a side-by-side, island-in-the-sea or sheath-core configuration.Preferable is that the additional polymer is selected from the groupconsisting of polyester, polyamide, polyvinyl chloride, cellulosecarbamate, cellulose acetate, cupro, viscose, polyacrylonitrile,polyolefin, Teflon, hemp, wool, linen and cotton.

The manufacture of the cellulosic moulded body according to theinvention can be carried out by means of immersing the manufacturedmoulded body into an aqueous solution containing heavy metal, separatingthe aqueous solution containing heavy metal and optionally washing anddrying the Lyocell moulded body obtained. The loading processes arecarried out for between 1 minute and several hours, depending on theapplication area.

The cellulosic moulded body can remain in the aqueous solutioncontaining heavy metal for up to roughly four hours. The aqueoussolution containing heavy metal is preferably roughly 0.1 M in relationto the heavy metal contained in it.

A further possibility for manufacturing the cellulosic moulded bodyaccording to the invention, if a plant and/or animal material isincorporated in this body, is if first the plant and/or animal material,such as algae material reduced to small pieces and ground, is broughtinto contact with a heavy metal solution, such as a silver nitratesolution, and the mixture obtained in this way is then sprayed dry,whereby the grinding can take place dry or wet and under normal or highpressure. This material, endowed with heavy metal, can then beincorporated into the cellulosic moulded body according to the inventionduring the manufacture of this body. This material can, for example, besprayed onto a fibrous web for textile, technical or medical use,together with the normally used bonding agent, or alone, during themanufacture of the fibrous web, before the fibrous web is dried andprocessed into the final product. The ground, spray-dried or damp algaematerial, loaded with heavy metal, can also be added to the spinningsolution for the manufacture of the cellulosic moulded body.

The cellulosic moulded body according to the invention is particularlyusable as an antibacterial and/or fungicidal material, particularly asan antibacterial fibre, antibacterial fibrous web, hygiene article,medical protective clothing, antibacterial water filter, non-woven,filter material or antibacterial sponge. A further possible use concernsthe use as bandaging gauze for burn injuries.

The cellulosic moulded body according to the invention is particularlyusable as a filtering material for liquid and gaseous media in whichpollutants are contained, for example as a cigarette filter to removeheavy metals and other pollutants from the smoke. By using a cellulosicmoulded body according to the invention, for example, in the form ofmodified fibres in a cigarette filter that was loaded with palladium andcopper salts, toxic carbon monoxide can be converted into carbondioxide, in addition to the removal of heavy metals from the smoke. Thiscatalyst effect of copper and palladium salts in an aqueous solution, inorder to oxidize carbon monoxide into carbon dioxide or sulphur dioxideinto sulphur trioxide, is described in U.S. Pat. No. 3,790,662.

In particular, the following products can be manufactured from thecellulosic moulded bodies according to the invention:

If the Lyocell moulded body according to the invention is present in theform of fibres or filaments, yarns for weaving mills and knitting millscan be made for the manufacture of filtering materials on a fabric basisor for the manufacture of antibacterial fabrics that can be used forclothing and medical applications. Included in the yarns made of Lyocellfibres according to the invention that lie in the number range Nm1/1 to170/1, are:

Condenser yarns, which include flat yarns and tweed yarns and that caneither be manufactured purely of Lyocell or of different combinationswith wool, cashmere, silk, mohair, alpaca, polyester, polyamide and/orviscose;

Worsted yarns, which include Siro, crepe and cordonnet yarns, that caneither be manufactured purely of Lyocell or of different combinationswith shear wool, cashmere, silk, mohair, alpaca, polyester, polyamideand/or viscose;

Ring spun yarns, carded or combed, that can either be manufacturedpurely of Lyocell or of different combinations with cotton, silk, linen,microfibres and/or viscose;

OE yarns, which can either be manufactured purely of Lyocell or ofdifferent combinations with cotton, wool, linen and/or viscose;

Fibre-effect yarns, which include boucle, terry, ondé twisted yarns, andthat can either be manufactured purely of Lyocell or of differentcombinations with cotton, silk, polyester, polyamide and/or viscose;

Filament-effect yarns, which include sable, terry, shaded and slubyarns, and that can either be manufactured purely of Lyocell or ofdifferent combinations with polyester, polyamide, viscose and/or TreviraCS;

Filament yarns, flat, textured or high-twist, that can either bemanufactured purely of Lyocell or of different combinations withacetate, triacetate, polyester, polyamide and/or viscose;

Technical yarns, which include, for example, Parafil Plyfil or Corespun,and that can either be manufactured purely of Lyocell or of differentcombinations with Kevlar, Preox, Nomex, Kermel, carbon, glass, steel,viscose and/or polyester; and

Elastic yarns, which include, for example, wrap yarn, Siro, Plyfil orCorespun, and that can either be manufactured purely of Lyocell or ofdifferent combinations with cotton, shear wool, polyester, linen,elasthan and/or viscose.

The combinations with other fibres have the advantage that the product'swearing comfort and properties for hygienic applications and clothingcan be adjusted using mixture components. The antibacterial propertiesor ion exchange properties are not impaired by this.

These yarns can be processed into fabrics using, for example, shuttle,rapier, projectile or jet machines, which, for example, are extremelywell suited for the application areas of ion exchange and antibacterialproperties. Likewise, the yarns can be processed into knitted fabricsusing flat bed, single jersey, double knit and warp knit machines, whichare likewise extremely well suited for the application areas of ionexchange and antibacterial properties.

Furthermore, the Lyocell moulded bodies according to the invention,optionally in the form of fibres/filaments, can be further processedinto endless or cut form to non-woven products for industrial uses, suchas roofing materials, separators, filters, reinforcing basic bodies,sealing materials and insulating materials, for special papers such asdust filters, filters for waste and/or process waters, sausage casings,for textile applications such as medical applications (swabs and gauze),wadding, stockings, shoe inserts, shoe inner lining, bedding, hometextiles, serviettes, washing clothes, paper towels or nappies.

The fabrication can either be processed into pure Lyocell products or incombination with other fibres, with super absorbers, with activatedcarbon and with native cellulose (fluff cellulose) in order to achieve acombination effect.

Consequently, combinations with super absorbers display extremely highabsorption of water; the combination with activated carbon in granulateor fibre form also shows, in addition to an antibacterial effect and anion exchange effect, an extra capability of adsorbing organic materialsand/or colouring substances.

It is also possible to add natural and synthetic bonding agents, such aslatex polymers, diethylene, butadiene, vinyl acetate and/or styrenes tothe cited bonded fabrics. These bonding agents are preferably added inan amount of from 1-30% by weight. Furthermore, thickeners, catalysts,filler materials, colouring substances, lubricants, optical bleachingagents and/or defoamers can be added.

The manufacture of the non-wovens or fibrous webs can take place using acarding, wetlaid, airlaid or extrusion process.

The fibrous webs manufactured in this way can be compacted by means ofneedlepunch, stitch bond, hydroentanglement, spun bond or melt blowingtreatment. Additional possibilities are chemical compaction with acorresponding bonding agent or thermal compaction or the admixing ofthermoplastic additives, which are compacted into a fibrous web with thecellulosic fibres.

In a finisher stage, the non-woven products can additionally bechemically and/or mechanically treated, in order, for example, tooptimize moisture absorption and moisture transport, or to improve theabsorption capability, fire resistance, electrical resistance, frictionproperties and/or abrasion properties.

Included in the mechanical aftertreatments are, among others,calendering, suede finishing, raising the nap, polishing, shearing andbrushing or combing. Further aftertreatment techniques are lamination,embossing and profiling using a calender or creping.

The non-woven products can be constructed in one or more layers andpresent a typical mass per unit area from 15-500 g/m².

Furthermore, the cellulosic moulded bodies can find application in theform of antibacterial sponges or sponge wipes.

These can be obtained according to the continuous manufacture of viscosesponges described in U.S. Pat. No. 3,382,303. Cellulose xanthate isdiluted with an aqueous solution, in which cellulose, reduced to smallpieces, is dispersed as a reinforcing agent for the sponge to be formed.Crystals of sodium sulphate or sodium phosphate are then added to thispaste. This paste is extruded in a form, open at the top, and fedthrough a precipitation bath at 95° C. for approximately 15 minutes.Final regeneration takes place in a second bath at 55-75° C. In thefurther sequence, the sponge is then washed, bleached, washed again andthen dried. Before the drying, the sponge is squeezed in order to reducethe water content.

A moulded body, according to the invention and with antibacterialeffect, is manufactured by adding a heavy metal, in metallic, ionic orcomplexed form, during an extra process step, for example either beforeor after the drying. Preferred embodiments can be derived from thefollowing examples.

Furthermore, Lyocell sponges according to the invention can be obtainedas described in WO 99/27835. In this process, a pore-forming agent andfibre reinforcement are mixed in with the N-oxide water cellulosesolution and the mass is applied to a conveyor belt using sheeting dies.The sedimentation takes place in a warm spinning bath in order toliquefy and dissolve the pore-forming agent. One variant is applicationof the N-oxide water cellulose solution to a plastic net. No blowingagent is used, so that neither the mechanical stability nor acorresponding abrasion. resistance of the sponge or sponge wipe can beachieved. WO 99/27835 describes impregnation of the sponges withsubstances with a biocide effect, such as isothiazolon, benzimidazolederivatives, tertiary ammonia salts, zeolites, glycerine and propyleneglycol.

A further method for manufacturing Lyocell sponges according to theinvention is similarly described in WO 97/23552. In this process, acellulose solution of an aqueous amine oxide is mixed with apore-forming agent (an alkaline salt or alkaline earth salt or aninorganic acid, e.g., Na₂SO₄) and a blowing agent. Then the mass issubjected to conditions that lead to decomposition of the blowing agentand therefore to a foaming of the cellulose solution. The foamedcellulose solution is brought into contact with water in order toprecipitate the cellulose and wash out the pore-forming agent.

A Lyocell sponge according to the invention, with an antibacterialeffect, is manufactured by adding a heavy metal in metallic, ionic orcomplexed form, during an extra process step either before or after thedrying. The detailed embodiment can be derived from the followingexamples.

Carbamate sponges according to the invention can be manufacturedanalogously to the method described in JP21172302, whereby again heavymetal is added at any stage of the process, preferably again before orafter the sponge is dried.

In the following, the invention is explained by using examples.

EXAMPLE 1

3250 g NMMNO (60.5%), 331 g MoDo, DP 500, solid content 94%, 2.0 gpropyl gallate (˜0.63% referred to the cellulose content) as well as 40g of the brown algae Ascophyllum nodosum (broken into small pieces) weremixed and the mixture obtained in this way was heated to 94° C. Adiscontinuously produced spinning solution with a cellulose content of12%, a solids content of 13.4% and a viscosity of 5,264 Pa.s wasobtained. The spinning solution obtained in this way was spun intofibres, whereby the following spinning conditions were maintained:

Storage tank temperature = 90° C. Spin block temperature, nozzle = 80°C. Spinning bath = 4° C. Spinning bath concentration (start) = 0%(distilled water) Spinning bath concentration (end) = 5% NMMNO Spinningpump = 0.6 cm³/r Nozzle filter = 19200 M/cm² Spinning nozzle = 500 hole90 μm; Au/Pt Final take-off = 30 m/min

The fibres were cut to a fibre staple of 40 mm, washed without solventand given a 10 g/l softening (50% Leomin OR-50% Leomin WG (fatty acidpolyglycol ester containing nitrogen, from the company Clariant GmbH))at 45° C. or the fat overlay for improved further processing of thefibre was applied and dried at 105° C.

After the drying, fibre moisture of 11% was regulated. No additionalbleaching process was carried out before the drying.

TABLE 1 Example 1 Part 1 Fineness, titre [dtex] 1.58 FB tear strength,dry [cN/tex] 40.0 FB tear strength, wet [cN/tex] 32.4 FB tear strength,loop [cN/tex] 7.1 Maximum tensile force elongation, dry [%] 10.7 Maximumtensile force elongation, [%] 12.3 wet Wet module [cN/tex] 225

Table 1 shows that the spinning characteristics of the spinning solutionobtained according to this example were good.

EXAMPLE 2

Lyocell cellulose fibres were continuously manufactured according toExample 1, whereby the respective amount, the conditions of thecontinuously maintained process and the physical properties of thefibres obtained are listed in the following Table 2. 8% brown algaematerial, referred to the cellulose, was used.

Table 2 presents the fibre data for the modified Lyocell fibre.

TABLE 2 Modified Lyocell fibre, manufactured continuously Fineness,titre [dtex] 1.34 FB tear strength, dry [cN/tex] 35.9 FB tear strength,wet [cN/tex] 31.1 FB tear strength, loop [cN/tex] 11.2 Maximum tensileforce [%] 11.9 elongation, dry Maximum tensile force [%] 13.4elongation, wet Wet module [cN/tex] 210

EXAMPLE 3

Furthermore, Lyocell fibres were continuously manufactured according toExample 1, with the difference that no brown algae material was added.

The physical data of the fibres obtained are summarized in the followingTable 3.

TABLE 3 Lyocell fibre, manufactured continuously Fineness, titre [dtex]1.4 FB tear strength, dry [cN/tex] 42.2 FB tear strength, wet [cN/tex]36.3 FB tear strength, loop [cN/tex] 15.2 Maximum tensile force [%] 15.5elongation, dry Maximum tensile force [%] 15.2 elongation, wet Wetmodule [cN/tex] 202

The analysis of the fibres produced in Examples 2+3 with regard to theirmetal ion content can be derived from the following Table 4.

The metal ion content was determined according to the testing method:

-   -   1. Microwave decomposition and    -   2. Metal determination according to DIN EN ISO 11885 (E22)

TABLE 4 Modified Lyocell fibre Example 2 - untreated Lyocell fibre[mmol/ Example 3 - untreated [mg/kg fibre] kg fibre] [mg/kg fibre][mmol/kg fibre] Arsenic <5 <DL <5 <DL Silver <2 <DL <2 <DL Antimony <5<DL <5 <DL Tin <5 <DL 6.1 0.05 Cadmium <1 <DL <1 <DL Copper <5 <DL <5<DL Lead 5.4 0.03 5.5 0.03 Zinc <5 <DL <5 <DL Calcium 115 2.87 38 0.95Magnesium 112 4.61 95 3.91 Sodium 330 14.35 306 13.31 Mercury <1 <DL <1<DL DL = Detection Limit

From Table 4, it is apparent that, in particular, calcium, magnesium andsodium ions are contained in the fibres.

EXAMPLE 4

1 l of 0.05 M AgNO₃ solution was added to 30 g of the fibres producedaccording to Example 1 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water until no more silver traces(test with a NaCl solution) were detected.

The fibres were dried in a circulating air drying cabinet atapproximately 105° C.

The fibre obtained in this way was analysed for its silver content. Forthis purpose, to a portion of the fibre material 1N nitric acid (1 hour)was added in order to dissolve the silver. The nitric acid solution wasfiltered off and then titrated with 0.1 N NaCl. To improve thevisibility of the end point of the titration, the filtrate was heated sothat the resulting precipitate agglomerated.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 5

1 l of 0.1 M CuSO₄ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 6

1 l of 0.1 M ZnSO₄ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 7

1 l of 0.1 M Hg(NO₃)₂ solution was added to 30 g of the fibres producedin Example 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 8

1 l of 0.1 M SnCl₄ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 9

1 l of 0.1 M CdSO₄ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 10

1 l of 0.1 M AgNO₃ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 11

1 l of 0.1 M As₂O₃ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 12

1 l of 0.1 M Pb(NO₃)₂ solution was added to 30 g of the fibres producedin Example 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 13

1 l of 0.1 M SbCl₅ solution was added to 30 g of the fibres produced inExample 2 and shaken for four hours.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water. The fibres were dried in acirculating air drying cabinet at approximately 105° C.

30 g of the fibres produced in Example 3 were treated in the same way.

EXAMPLE 14

The maximum amount of the fibres produced according to Examples 4 to 13that could be taken up on the respective metal ions was examined.

The results are summarized in the following Table 5.

TABLE 5 Modified Lyocell fibre Lyocell fibre Example 2 Example 3 [mg/kgfibre] [mmol/kg fibre] [mg/kg fibre] [mmol/kg fibre] Example 4 Silver1855 17.2 237 2.2 Example 5 Copper 899 14.2 591 9.3 Example 6 Zinc 75611.6 526 8.0 Example 7 Mercury 9460 47.2 376 1.9 Example 8 Tin 1670 14.11030 8.7 Example 9 Cadmium 1270 11.3 793 7.1 Example Silver 1410 13.1207 1.9 10 Example Arsenic 170 2.3 72 1.0 11 Example Lead 2720 13.1 17908.6 12 Example Antimony 496 4.1 267 2.2 13

What is surprising is that the Lyocell fibres present a high adsorptioncapacity, and that this adsorption capacity can be increased by another50% with the modified Lyocell fibres.

EXAMPLE 15

The fibres produced according to Example 4 were then examined forbacterial resistance.

The determination was carried out following the Japanese IndustrialStandard, JIS L1902:1998 Testing method for antibacterial of textiles.Staphylococcus aureus, as a gram-positive bacterial strain, andKlebsiella pneumoniae, as a gram-negative bacterial strain, were used.

The bacteria were furthermore applied to fibre material from Example 1and, as a growth control, standard cotton was subjected to the same testtreatment.

After 18 hours of incubation, the bacterial growth inhibiting orbacterial reduction activity is determined from the bacterial content(the number of colony-forming units—CFU) in the sample and the control.

To calculate this antibacterial activity, the difference in the base-10logarithms of the number of colony forming units (CFU) in the controlsample and the sample, each after 18 hours of incubation, is formed.

The classification is done in three classes—slight activity, significantactivity and strong activity=“activity value for bacteriostat”. Slightactivity indicates a difference of zero logarithm steps between thecontrol and the sample, significant activity indicates a difference ofmore than 1 and strong activity indicates a difference of more than 3.

While the cotton and the untreated fibres according to Example 1displayed no antibacterial effect, no more bacteria could be detected onthe fibres treated with silver nitrate according to Example 4. Thismeans that the fibres treated with silver showed a strong antibacterialeffect.

In the following Table 6, the levels after 18 hours of incubation arespecified for the standard cotton as a growth control and for a standardLyocell fibre and the modified Lyocell fibre produced according toExample 1. Furthermore, the treated, modified Lyocell fibres producedaccording to Example 4 and a similarly treated standard Lyocell fibreare listed.

TABLE 6 Staphylococcus aureus Klebsiella pneumoniae conc. after 18 hoursconc. after 18 h [log CFU] [log CFU] Standard cotton 5.62 7.38 Lyocellfibre, untreated, 5.51 7.85 Example 3 Modified Lyocell fibre, 6.25 7.92untreated, Example 1 Lyocell fibre, treated, 0 0 similar to Example 4Modified Lyocell fibre, 0 0 treated, similar to Example 4

EXAMPLE 16

In the manufacture of high-purity silver, an anode of raw silver issubjected to electrolytic refining in conventional Moebius cells. Inthis process, silver nitrate, as an electrolyte, is used at aconcentration of 5-80 g/l of silver at a temperature of 40° C. While itis true that the electrolyte is constantly reused, nevertheless, duringmaintenance work and standstills, waste waters with silverconcentrations that are also partially less than in the electrolyte dooccur. The recovery of the silver nitrate by means of the Lyocellmoulded body according to the invention was tested using a syntheticsilver nitrate solution. 2 kg of fibre from Example 2 were filled into a5 l PP pressure tank with backup plate. The fibre was subsequentlymoistened with 5 l of completely demineralised water. 10 l of silvernitrate, at a concentration of approximately 1 g Ag/l, were introducedinto a PP container. Using a constricted tube pump, this quantity waspumped over the pressure tank (with the moistened fibres from Example 3)to recirculate. With the built-in rotameter, a recirculation flow rateof 30 l/h was selected.

A sample was drawn every 5 minutes in order to determine the Agconcentration. The following Table 7 presents the progression of thesilver amount in the liquid phase.

It could be shown that practically all of the silver is absorbed fromthe fibre.

TABLE 7 Silver amount in Time the liquid phase [g] 5 9.6 10 7.8 15 5.420 4.7 25 4.1 30 2.9 35 1.4 40 1.3 45 0.8 50 0.6 55 0.37 60 0.34 65 0.2570 0.26 75 0.23

FIG. 1 is a graphic representation of the results obtained in thisexample.

EXAMPLE 17

To 30 g of a Lenzing modal fibre (titre fineness: 0.12 tex, from thecompany Lenzing AG) 1 l of 0.1 M AgNO₃ solution was added and shaken forfour hours. The treatment took place analogously to Example 10.

After this treatment, the fibre material was filtered by suction andwashed with completely demineralised water until no more silver traces(test with a NaCl solution) were detected.

The fibres were dried in a circulating air drying cabinet atapproximately 105° C.

The fibre obtained in this way was analyzed for its silver content. Forthis purpose, to a portion of the fibre material 1 N nitric acid wasadded (1 hour) in order to dissolve the silver. The nitric acid solutionwas filtered off and then titrated with 0.1 N NaCl. To improve thevisibility of the end point of the titration, the filtrate was heated sothat the resulting precipitate agglomerated.

TABLE Modified modal fibre Example 17 [mg/kg fibre] Example 17 Silver351

EXAMPLE 18

The fibres produced according to Example 17 were then examined forbacterial resistance.

The determination took place analogously to Example 15.

The determination was carried out following the Japanese IndustrialStandard, JIS L1902:1998 Testing method for antibacterial of textiles.Staphylococcus aureus, as a gram-positive bacterial strain, andKlebsiella pneumoniae, as a gram-negative bacterial strain, were used.

The bacteria were applied to fibre material from Example 17 and, as agrowth control, standard cotton and cellulose were subjected to the sametest treatment.

After 18 hours of incubation, the bacterial growth inhibiting orbacterial reduction activity is determined from the bacterial content(the number of colony-forming units—CFU) in the sample and the control.

To calculate this antibacterial activity, the difference is formedbetween the base-10 logarithms of the number of colony forming units(CFU) in the control sample and the sample, each after 18 hours ofincubation.

The classification is done in three classes—slight activity, significantactivity and strong activity=“activity value for bacteriostat”. Slightactivity indicates a difference of zero logarithm steps between thecontrol and the sample, significant activity indicates a difference ofmore than 1 and strong activity indicates a difference of more than 3.

While the cotton and the cellulose displayed no antibacterial effect, nomore bacteria could be detected on the fibres treated with silvernitrate according to Example 17. This means that the fibres treated withsilver showed a strong antibacterial effect.

In the following table, the levels after 18 hours of incubation arespecified for the standard cotton and cellulose as a growth control andfor a modified Lyocell fibre produced according to Example 17.

Staphylococcus aureus Klebsiella pneumoniae conc. after 18 conc. after18 hours [log CFU] hours [log CFU] Standard cotton 3.32 7.52 Standardcellulose 5.80 7.54 Modified modal fibre in 0 0 accordance with Example17

EXAMPLE 19

The washing out characteristics of a Lyocell fibre with algaeincorporation (Example 2) treated according to Example 10 (with 0.1 MAgNO₃) was tested in the following way:

25 g of the dried fibre were prepared in a liter of completelydemineralised water. The water was examined qualitatively after standingfor 24 hours. After the sample was taken, the fibre material wassqueezed out and supplied with new completely demineralised water. Thisprocess was repeated 4 times (a total of 4 phases of 24 hours each). Thesilver content of the fibre was determined before and after the testseries. The data are summarized in the following Table.

EXAMPLE 20

The washing out characteristics of a Lyocell fibre (Example 3 treatedaccording to Example 10 (with 0.1 M AgNO₃)) was tested in the same wayas described in Example 19.

The data are summarized in the following Table.

EXAMPLE 21

The washing out characteristics of a Lenzing viscose modal fibre (titrefineness: 0.12 tex, from the Lenzing AG company) was treated accordingto Example 17 (with 0.1 M AgNO₃) and tested in the same way as describedin Example 19.

The data are summarized in the following Table.

Silver content of the fibre [mg/kg fibre] After the After the After theAfter the 1^(st) phase 2^(nd) phase 3^(rd) phase 4^(th) phase Time Atthe start (24 h) (24 h) (24 h) (24 h) Example 19 - 1842 1605 1427 12781191 modified Lyocell with algae incorporation Qualitative silverdetection in completely demineralised water for Silver content of eachwashing phase the fibre [mg/kg 1^(st) 2^(nd) 3^(rd) 4^(th) fibre] phasephase phase phase Time At the start After the end (24 h) (24 h) (24 h)(24 h) Example 19 - 1842 1191 Pos. Pos. Pos. Pos. modified Lyocell withalgae incorporation Example 20 - 216 63 Pos. Pos. Pos. Pos. modifiedLyocell without algae incorporation Example 21 - 351 111 Pos. Pos. Pos.Pos. modified viscose modal with algae incorporation

EXAMPLE 22

Fibre loaded with silver, from Example 10, was mixed with normal Lyocellfibre from Example 3, so that an Ag concentration of approximately 100mg of Ag/kg fibre was present in the mixture.

A card sliver was produced from this mixture for homogenizationpurposes, and this card sliver was examined for antibacterial propertiesaccording to Example 18. In the following table, the levels after 18hours of incubation are specified for the standard cotton and celluloseas a growth control and for the modified Lyocell fibre producedaccording to Example 22.

EXAMPLE 23

Fibre loaded with silver, from Example 10, was mixed with normal Lyocellfibre from Example 3, so that an Ag concentration of approximately 50 mgAg/kg fibre was present in the mixture.

A card sliver was produced from this mixture for homogenizationpurposes, and this card sliver was examined for antibacterial propertiesaccording to Example 18. In the following table, the levels after 18hours of incubation are specified for the standard cotton and celluloseas a growth control and for the modified Lyocell fibre producedaccording to Example 22.

EXAMPLE 24

Fibre loaded with silver, from Example 10, was mixed with normal Lyocellfibre from Example 3, so that an Ag concentration of approximately 5 mgAg/kg fibre was present in the mixture.

A card sliver was produced from this mixture for homogenizationpurposes, and this card sliver was examined for antibacterial propertiesaccording to Example 18. In the following table, the levels after 18hours of incubation are specified for the standard cotton and celluloseas a growth control and for the modified Lyocell fibre producedaccording to Example 22.

Staphylococcus Klebsiella aureus pneumoniae conc. conc. after 18 h [logafter 18 hours CFU] [log CFU] Standard cotton 3.32 7.52 Standardcellulose 5.80 7.54 Card sliver with approx. 100 mg Ag/kg 0 0 fibre -Example 22 Card sliver with approx. 50 mg Ag/kg 0 0 fibre - Example 23Card sliver with approx. 5 mg Ag/kg 0 0 fibre - Example 24

EXAMPLE 25

3210 g NMMNO (60.5%), 321 g MoDo, DP 500, solid content 94%, 2.0 gpropyl gallate (˜0.63% referred to the cellulose content) as well as 26g of the brown algae Ascophyllum nodosum (broken into small pieces) and20 mg silver (I) oxide (broken into small pieces—max. size 1.5μm—supplier: Sigma Aldrich, Product Number 10228) were mixed and themixture obtained in this way was heated to 94° C. A discontinuouslyproduced spinning solution with a cellulose content of approximately11.8%, a solids content of 12.7% and a viscosity of 5,264 Pa.s wasobtained. The spinning solution obtained in this way was spun intofibres, whereby the following spinning conditions were maintained:

Storage tank temperature = 90° C. Spin block temperature, nozzle = 80°C. Spinning bath = 4° C. Spinning bath concentration (starting) = 0%(distilled water) Spinning bath concentration (end) = 5% NMMNO Spinningpump = 0.6 cm³/r Nozzle filter = 19200 M/cm² Spinning nozzle = 500 hole90 μm; Au/Pt Final take-off = 30 m/min

The fibres were cut to a fibre staple of 40 mm, washed without solventand given a 10 g/l softening (50% Leomin OR-50% Leomin WG (fatty acidpolyglycol ester containing nitrogen, from the company Clariant GmbH))at 45° C. or the fat overlay was applied for improved further processingof the fibre and dried at 105° C.

After the drying, fibre moisture of 11% was regulated. No additionalbleaching process was carried out before the drying.

EXAMPLE 26

A cellulose xanthate was produced from a mixture of 33% cellulose byweight, 17% caustic soda solution by weight and 50% water by weight byadding 32% carbon disulfide referred to the cellulose. Following this,the xanthate was converted to a spinning solution with 6% cellulose byweight, 6% NaOH by weight and essentially water and reaction products byadding diluted caustic soda solution subsequent to the xanthateproduction by 2 hours of stirring.

EXAMPLE 27

60 g of sodium sulphate (Glauber's salt) as a pore-forming agent and 5 gof viscose short cut fibres (Svenska Rayon Company, Swelan type with 1.0dtex, 5 mm) were added to 1.5 kg of the viscose solution obtained fromExample 26 and intensively stirred.

The mass was filled into a perforated form and placed for 30 minutesinto a first precipitation bath that was at a temperature of 95° C. andthat contained 10 g/l of sodium carbonate and 80 g/l of sodium sulphate.

Subsequently, the pre-precipitated mass was transferred to a second bathfor 15 minutes; this bath's temperature was 60° C. and it contained 70g/l sulphuric acid and 140 g/l sodium sulphate, in order to completelyregenerate the cellulose.

Then the sponge was washed, squeezed out and dried.

EXAMPLE 28

The sponge is produced analogously to Example 27, whereby an additional8 g of brown algae powder, finely reduced to small pieces, was added tothe viscose solution.

The dried and desulphurised sponge was then transferred to a bath of 0.1N silver nitrate and left in the bath for approximately 1 hour. Thesponge containing Ag was then washed free and dried again.

Like all other manufactured sponges, the sponge was examined forantibacterial properties.

The determination was carried out following the Japanese IndustrialStandard, JIS L1902:1998 Testing method for antibacterial of textiles.Staphylococcus aureus, as a gram-positive bacterial strain, andKlebsiella pneumoniae, as a gram-negative bacterial strain, were used.

The bacteria were applied to the sponge and, as a growth control, thestandard sponge from Example 27 was subjected to the same testtreatment.

After 18 hours of incubation, the bacterial growth inhibiting orbacterial reduction activity is determined from the bacterial content(the number of colony-forming units—CFU) from the sample and thecontrol.

While the standard sponge from Example 27 displayed no antibacterialeffect, no more bacteria were detected on the sponge from Example 28.This means that the sponge with incorporated brown algae and treatedwith silver displays a strong antibacterial effect because of theattachment of the silver ions to the incorporated brown algae material.

EXAMPLE 29

A sponge was produced analogously to Example 27. There was, however, noaddition of algae powder and no addition of viscose short cut fibres;instead, 35 g of a short cut Lyocell fibre with incorporated algae (12%algae referred to the cellulose—produced according to WO 01/62844) wasadded. A sponge was produced analogously to Example 28 and treated withsilver nitrate.

This sponge also displayed a strong antibacterial effect.

Carbamate Sponges

EXAMPLE 30

To produce cellulose carbamate, first an alkali cellulose was producedfrom the chemical cellulose Borregaard SVS. The caustic soda solutionwas washed out of the processed alkali cellulose (35% cellulose byweight; 15% NaOH by weight; 50% water by weight) with water. After thecellulose (70% water by weight) activated in this way was squeezed out,10 kg of the squeezed activated cellulose were mixed with carbamide (1.5kg) in a kneading machine. In this process, the carbamide present in thewater in the cellulose dissolved and was uniformly distributed in thecellulose.

This cellulose pulp was transferred to a reactor, which was equippedwith a mixer and reflux cooler, and which already contained o-xylene (35kg). The reactor contents were then heated to 145° C. for approximately2 hours and then filtered off.

The residue obtained in this way was fed back into the reactor, in whichapproximately 25 kg of water had been placed. The xylene that was stilladhering to the carbamate was stripped off at 88° C. After thefiltration, the carbamate was washed out with hot (50° C.) and coldwater. Then the carbamate was squeezed out. The produced carbamatedisplayed a nitrogen content of 2.6% (corresponds to a DS of 0.3) and aDP of 270.

EXAMPLE 31

Approximately 0.7 kg of strong solution were produced from 0.2 kg of thecarbamate produced in Example 30, along with 0.22 kg caustic sodasolution (30% by weight), 0.26 kg water and 10 g of brown algae powder,finely broken down, type Ascophyllum nodosum. All reactants werepre-cooled and the reaction itself took place at a temperature of 0° C.(Composition of the strong lye: 11.0% cellulose by weight, 9.5% NaOH byweight.) To the cooled strong solution 65 g of sodium sulphate as apore-forming agent, 25 g of acid sodium carbonate as a blowing agent, 30g of viscose short cut fibres (Svenska Rayon Company, Swelan type with1.0 dtex, 5 mm) and 0.2 kg of cooled caustic soda solution (1%) wereadded and intensively stirred.

The mixture was transferred into a larger vacuum container and kept at100° C. for approximately 20 minutes. The decomposition gases were takenaway via applied vacuum.

The foamed mass was placed into a warm bath, approximately 40° C., madeof sulphuric acid (70 g/l) and sodium sulphate (140 g/l), for 10 minutesin order to precipitate the cellulose and fix the structure. After awashing step in completely demineralised water, the sponge was kept in ahot decomposition bath (85° C.) of caustic soda solution (20 g/l) andsodium sulphate (100 g/l) for 10 minutes. Then the sponge was washed,squeezed out and dried.

The neutrally washed and dried sponge was then transferred to a bath of0.1 N silver nitrate and left in the bath for approximately 1 hour. Thesponge containing Ag was then washed free and dried again.

The carbamate sponge displayed a strong antibacterial effect.

EXAMPLE 32

A sponge was produced analogously to Example 31, but there was noaddition of algae powder; instead, approximately 11 g of treated algaepowder was added.

The powder was treated in the following way: approximately 25 g of algaepowder, finely broken down, was treated for 1 hour with 1 l of 0.1 Nsilver nitrate solution. The treated powder was centrifuged off andwashed with water, then dried in a further step.

This sponge also displayed a strong antibacterial effect.

EXAMPLE 33

A sponge was produced analogously to Example 31. There was, however, noaddition of algae powder during the production of the strong solution.Furthermore, no viscose short cut fibres were added; instead, 45 g of ashort cut Lyocell fibre with incorporated algae was added (12% algaereferred to cellulose—produced according to WO 01/62844).

A sponge was produced analogously to Example 31 and treated with silvernitrate.

This sponge also displayed a strong antibacterial effect.

EXAMPLE 34

A sponge was produced analogously to Example 33. There was, however, anaddition of a short cut Lyocell fibre (treated with silver nitrate) withincorporated algae (12% algae referred to cellulose—produced accordingto WO 01/62844). The fibre was treated in the following way:approximately 100 g of fibre were treated for 1 hour with 3 l of 0.1 Nsilver nitrate solution. The fibre was filtered off, washed with waterand subsequently dried.

A sponge was produced analogously to Example 33, but not treated withsilver nitrate.

The sponge produced in this way displayed a strong antibacterial effect.

Lyocell Sponges

EXAMPLE 35

2967 g NMMNO (49.8%), 302 g MoDo, DP 500, dry content 94%, 1.8 g propylgallate (0.63% referred to the cellulose content) and 23 g of brownalgae powder, finely broken down (approximately 8% referred to thecellulose content), type Ascophyllum nodosum were mixed and the mixtureobtained in this way was heated to 94° C. A discontinuously producedspinning solution with a cellulose content of 14.2% was obtained.

In a heated kneading machine (IKA-Werke HKS 10), 1550 g of NMMOmonohydrate (86%) were dissolved by heating and mixed with 1450 g ofN,N-dimethylformamide (DMF), an organic solvent, in order to prepare oradjust the viscosity for mixing in the reinforcing fibres. This measurewas the first to solve the problem of the high viscosities predominantin the amine oxide-cellulose-water system for sponge manufacture (U.S.Pat. No. 4,196,282).

Then 30 g of viscose short cut fibres (Svenska Rayon Company, Swelantype with 1.0 dtex, 5 mm) and a pore-forming agent (90 g Na₂SO₄) werestirred into this mixture. Where necessary, a blowing agent can also beadded.

This mixture is then added to the spinning solution produced.N,N-dimethylformamide, with a boiling point of 153° C., was evaporatedunder vacuum (80 mbar), so that a homogenous cellulose solution,reinforced with fibre and with a cellulose concentration ofapproximately 8%, was regulated. It was observed that the cellulosicshort cut fibres swell during the distillation of the DMF, but do notcompletely become a solution, so that the sponge reinforcement effect isstill maintained after being shaped into the corresponding mouldedproduct.

The mass is then filled into a perforated form, approximately 7 mm high,and placed into a 50° C. precipitation bath mixture for 20 minutes.

The sponge goes through an additional 4 washing baths every 15 minutesto wash the solvent free; each bath contains completely demineralisedwater at a temperature of 30° C. Then the sponge is squeezed out anddried in a drying cabinet at 90° C. for approximately 2 hours.

Where necessary, a softening substance can be added to the sponge inorder to compensate for the brittleness.

The dried sponge was then transferred to a bath of 0.1 N silver nitrateand left in the bath for approximately 1 hour. The sponge containing Agwas then washed free and dried again.

The sponge treated with silver also displays a strong antibacterialeffect.

EXAMPLE 36

A sponge was produced analogously to Example 35, but there was noaddition of algae powder during the production of the solution; instead,approximately 25 g of treated algae powder was added along with theaddition of the pore-forming agent and short cut fibres.

The powder was treated in the following way: approximately 25 g of algaepowder, finely broken down, was treated for 1 hour with 1 l of 0.1 Nsilver nitrate solution. The treated powder was centrifuged off andwashed with water, then dried in a further step.

A sponge was produced analogously to Example 35, but not treated withsilver nitrate.

This sponge also displayed good rigidity and a strong antibacterialeffect.

EXAMPLE 37

A sponge was produced analogously to Example 35. There was, however, noaddition of algae powder during the production of the solution.Furthermore, no Lyocell short cut fibres were added; instead, threetimes as much Lyocell fibre with incorporated algae (12% algae referredto the cellulose—produced according to WO 01/62844) was added. A spongewas produced analogously to Example 35 and treated with silver nitrate.

In spite of the reduced amount of incorporated algae, this sponge alsodisplayed a strong antibacterial effect.

EXAMPLE 38

A sponge was produced analogously to Example 37. There was, however, anaddition of a short cut Lyocell fibre (treated with silver nitrate) withincorporated algae (12% algae referred to cellulose—produced accordingto WO 01/62844). The fibre was treated in the following way:approximately 100 g of fibre were treated for 1 hour with 3 l of 0.1 Nsilver nitrate solution. The fibre was filtered off, washed with waterand subsequently dried in a further step.

A sponge was produced analogously to Example 37, but not treated withsilver nitrate.

This sponge also displayed a strong antibacterial effect.

Information on the Assessment of the Antibacterial Effect:

The determination was carried out following the Japanese IndustrialStandard, JIS L1902:1998 Testing method for antibacterial of textiles.Staphylococcus aureus, as a gram-positive bacterial strain, andKlebsiella pneumoniae, as a gram-negative bacterial strain, were used.

The bacteria were applied to the sponge and, as a growth control,cellulose was subjected to the same test treatment.

After 18 hours of incubation, the bacterial growth inhibiting orbacterial reduction activity is determined from the bacterial content(the number of colony-forming units—CFU) in the sample and the control.

To calculate this antibacterial activity, the difference is formedbetween the base-10 logarithms of the number of colony forming units(CFU) in the control sample and the sample, each after 18 hours ofincubation.

The classification is done in three classes—slight activity, significantactivity and strong activity=“activity value for bacteriostat”. Slightactivity indicates a difference of zero logarithm steps between thecontrol and the sample, significant activity indicates a difference ofmore than 1 and strong activity indicates a difference of more than 3.The difference in the logarithm steps is also called the specificefficacy.

The bacteria were applied to the sponge and, as a growth control, thestandard sponge from Example 27 was subjected to the same testtreatment.

After 18 hours of incubation, the bacterial growth inhibiting orbacterial reduction activity is determined from the bacterial content(the number of colony-forming units—CFU) in the sample and the control.

While the standard cotton that was also measured as the control showedno antibacterial effect, a strong antibacterial effect was detected inthe sponges from Examples 3-13, as shown in the following table.

Specific efficacy Antibacterial effect Staphylococcus Klebsiella[slight, significant, aureus pneumoniae strong] Standard cotton +2.09−2.05 slight Example 28 +5.51 +7.85 strong (viscose) Example 29 +5.51+7.85 strong (viscose) Example 31 +5.51 +7.85 strong (carbamate) Example32 +5.01 +6.31 strong (carbamate) Example 33 +5.51 +7.85 strong(carbamate) Example 34 +4.65 +5.64 strong (carbamate) Example 35 +5.51+7.85 strong (Lyocell) Example 36 +5.21 +6.88 strong (Lyocell) Example37 +5.51 +7.85 strong (Lyocell) Example 38 +5.01 +6.45 strong (Lyocell)

The sponges according to the invention display the following advantages:

-   -   A necessary insolubility of the added bactericidal substances in        water, alkalis and acids in temperature ranges from 20-100° C.    -   A necessary chemical stability in the face of strong lyes and        strong acids and diverse oxidants.    -   Good miscibility of the substance with the bactericidal effect        with the cellulose solution to be formed without negatively        influencing the spinning process and shaping process, because it        is introduced indirectly via a biological carrier material, and        not directly.    -   The diffusion effect of the substances with a bactericidal        effect in the direction of the fibre surface is, naturally,        proven for biological substances such as cellulose and algae.    -   Good ecological and toxicological compatibility of the substance        with the bactericidal effect because, on the one hand, no        organic chlorine compounds are used and, on the other hand, the        bactericide is only released in connection with moisture.

1. A method for removing heavy metals from media containing heavymetals, comprising bringing the medium containing heavy metals intocontact with a Lyocell moulded body, wherein the Lyocell moulded bodycomprises an algae material.
 2. The method according to claim 1, whereinthe Lyocell moulded body is an ion exchanger or filtering material. 3.The method according to claim 1, wherein the medium containing heavymetals is an aqueous solution or a gas.
 4. The method according to claim1, wherein the heavy metals are selected from the group consisting ofAg, Cu, Zn, Hg, Sn, Cd, As, Pb, Sb, Zr, Ni, Fe, Au, Pd, Pt, Ir andmixtures thereof in metallic, ionic and/or complexed form.
 5. The methodaccording to claim 1, wherein the Lyocell moulded body is in the form offibres, filaments, fibrous webs, foils, films, membranes, non-wovens,filters, cigarette filters and/or filter papers.
 6. A cellulosic mouldedbody, comprising at least one heavy metal adsorbed on it, wherein thecellulosic moulded body comprises an algae material.
 7. The cellulosicmoulded body according to claim 6, wherein the cellulosic moulded bodyis selected from the group consisting of carbamate, viscose and Lyocellmoulded bodies.
 8. The cellulosic moulded body according to claim 6,wherein the content of the at least one heavy metal is at least roughly5 mg/kg, relative to the total weight of the cellulosic moulded body. 9.The cellulosic moulded body according to claim 6, wherein the at leastone heavy metal is selected from the group consisting of Ag, Cu, Zn, Hg,Sn, Cd, As, Pb, Sb, Zr, Ni, Fe, Au, Pd, Pt, Ir and mixtures thereof inmetallic, ionic and/or complexed form.
 10. The cellulosic moulded bodyaccording to claim 9, wherein the at least one heavy metal is selectedfrom the group consisting of Ag, Cu, Zn, Zr, Au and mixtures thereof inmetallic, ionic and/or complexed form.
 11. The cellulosic moulded bodyaccording to claim 6, wherein the cellulosic moulded body is in the formof fibres, filaments, fibrous webs, foils, films, membranes, non-wovens,cigarette filters and/or filters.
 12. The cellulosic moulded bodyaccording to claim 6, further comprising a natural or synthetic polymer.13. The cellulosic moulded body according to claim 12, wherein thenatural or synthetic polymer is selected from the group consisting ofpolyester, polyamide, polyvinyl chloride, cellulose carbamate, cupro,viscose, polyacrylonitrile, polyolefin, Teflon, hemp, wool, linen andcotton.
 14. An antibacterial fibre, comprising a cellulosic moulded bodyaccording to claim
 6. 15. An antibacterial fibrous web, comprising acellulosic moulded body according to claim
 6. 16. An antibacterialmembrane, comprising a cellulosic moulded body according to claim
 6. 17.An antibacterial sausage casing, comprising a cellulosic moulded bodyaccording to claim
 6. 18. A hygiene article, comprising a cellulosicmoulded body according to claim .
 19. Products with medicalapplications, comprising a cellulosic moulded body according to claim 6.20. Sterile protective clothing, comprising a cellulosic moulded bodyaccording to claim
 6. 21. An antibacterial water filter, comprising acellulosic moulded body according to claim
 6. 22. An antibacterialsponge, comprising a cellulosic moulded body according to claim
 6. 23. Acigarette filter, comprising a cellulosic moulded body according toclaim 6.